Method of and apparatus for placing continuous reinforcing in concrete paving

ABSTRACT

Continuous reinforcing rods are positioned on the grade to be paved and are lifted over a first machine which receives the concrete delivered alongside the grade and spreads the concrete under the rods and over the grade. Tie bars or crossbars are then placed on top of the concrete in such a manner as to be beneath the continuous reinforcing rods. The rods are then guided and depressed below the surface of the concrete by a second concretefinishing machine and in turn depress the tie bars or crossbars to their proper position immediately therebeneath.

United States Patent Michael I. Hudis Brookiield, Wis. 14,547

Feb. 26, 1970 Oct. 12, 1971 Rex Chainbelt Inc. Milwaukee, Wis.

Inventor App]. No. Filed Patented Assignee METHOD OF AND APPARATUS FOR PLACING CONTINUOUS REINFORCING IN CONCRETE PAVING 22 Claims, 8 Drawing Figs.

US. Cl 94/39 E0lc 19/00 Field of Search 94/39, 46

References Cited UNITED STATES PATENTS 4/1963 Wooley 94/39 3,329,073 7/1967 Devereaux.... 3,331,296 7/1967 Perkins Primary Examiner-Jacob L. Nackenoff Attorney-Sughrue, Rothwell, Mion, Zinn & MacPeak ABSTRACT: Continuous reinforcing rods are positioned on the grade to be paved and are lifted over a first machine which receives the concrete delivered alongside the grade and spreads the concrete under the rods and over the grade. Tie bars or crossbars are then placed on top of the concrete in such a manner as to be beneath the continuous reinforcing rods. The rods are then guided and depressed below the surface of the concrete by a second concrete-finishing machine and in turn depress the tie bars or crossbars to their proper position immediately therebeneath.

PATENTED 0m 1 2 m SHEEI 2 OF 4 PATENIED an? 1 2 I971,

sum 3 or 4 PAIENTEnum 2m: 3351 1.890

SHEET t [1F 4 METHOD OF AND APPARATUS FOR PLACING CONTINUOUS REINFORCING IN CONCRETE PAVING CROSS-REFERENCE TO RELATED APPLICATION The present inventors copending application, Ser. No. 8,222, filed- Feb. 3, 1970, and of the same title discloses in part the subject matter of the present application.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method of and apparatus for placing continuous reinforcing rods in concrete paving.

2. Description of the Prior Art The layihg of concrete paving is accomplished generally by two methods. These methods are: (1) the fixed-form method, whereby forms are placed along both sides of the roadway to be paved prior to pouring of the concrete. The concrete is then poured onto the grade between these fixed forms and allowed to set prior to the removal of the forms; (2) the slipform method, which incorporates'the use of moving forms located on either side of the paving machine and corresponding to the. sides of the roadway to-be paved. Concrete is placed on the grade ans is distributed between the forms, struck off and finished by the paving machine, thus leaving behind a plastic concrete slab which needs only to harden to constitute a finished, paved roadway. The slip-form method requires no removal of forms from the roadway after the pavement has set.

Various. reinforcing means are used with both the fixedform and slip-form type of paving to strengthen the concrete pavement. These reinforcing means include the use of continuous reinforcing rods or wire mesh placed beneath the surface of the concrete pavement. Various methods have been used to locate such reinforcing means in the concrete pavement. These methods have included pouring a first layer of concrete of the desired thickness, manually placing the reinforcing rods or wire mesh upon the first-poured layer, and then pouring a second layer of concrete over the reinforcing rods. Another method involves the supporting of the continuous reinforcing rods at the desired height by the slip-form paving machine while simultaneously pouring and finishing the concrete around the rods and their supporting means. In the latter method, the closely spaced rods and their supporting means tend to interfere with the uniform settlement of the concrete onto the roadbed.

SUMMARY OF THE INVENTION According to the present invention, continuous reinforcing rods are supported above and pass over a first machine or spreader which receives the concrete from delivery vehicles operating alongside the roadbed and distributes the concrete onto the roadbed beneath the rods. The continuous reinforcing rods are then guided and depressed into the plastic concrete to a predetermined level by a second paving machine or finisher which respreads the concrete over the depressed reinforcing rods and forms a finished surface on the plastic concrete. Although the preferred embodiment of the invention utilizes the slip-form method of paving, it is equally suitable for use with the fixed-form method.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is a side elevational view of a preferred embodiment of the first machine or spreader;

FIG. 2 is a partial top plan view of the first machine;

FIG. 3 is a sectional view, with parts broken away, taken substantially along line 3-3 in FIG. 2;

FIG. 4 is a front elevational view of the first machine, with parts broken away, showing a first embodiment of the retractable concrete-receiving conveyor;

FIG. 5 is a side elevational view of a preferred embodiment of the second paving machine or finisher;

FIG. 6 is apartial top plan view of the second machine;

FIG. 7 is a partial front elevational view of the first machine, with parts broken away and omitted, showing a second embodiment of the retractable concrete-receiving conveyor; and

FIG. 8 is a side elevational view of the rear portionof a modified form of the first machine having a rear-platform for the support and dispensing of full-width reinforcing crossbars.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As seen in FIGS. 1-4, the first machine or spreader 10 comprises a pair of endless track-laying carriages l l which operate on the grade G at each side of the roadway to be formed. A support frame 12 is mounted on the carriages 11 and comprises upwardly extending beams 13 and transverse beams 14. Power means 15 and an operator control deck l6 are spaced above and supported by the frame 12. The power means 15 is electrically or hydraulically connected inany suitable manner to the drive means 17 and the sprockets .18 for driving the endless tracks 19 of the carriages 11.

Each carriage 11 includes a slip form 20 which extends rearwardly of the spreader 10 to form the side of the concrete slab C as it is laid on the grade G. As is well known, the spreader 10 may be guided by probes (not shown) which move alonga guide wire (not shown).

A concrete-receiving conveyor 21 is mounted on the frame 12 to receive mixed concrete from a delivery vehicle (not shown) to be distributed onto the grade G. As shown in FIGS. l-4, the conveyor means 21 comprises a belt conveyor 22 mounted on rollers 23, one of which is drivingly connected to the power means 15 in any suitable manner. The rollers 23 are supported by a frame 24 having guide rollers 25 that are disposed within guide channels 26 mounted on the frame 12 to enable the frame 24, and thus the belt conveyor 22, to be moved transversely by power means (not shown) between the positions shown in solid and broken lines in FIG. 4. In this manner, the belt conveyor 22 can be moved inwardly to allow concrete delivery vehicles (not shown) to pass closely adjacent to the spreader 10 when travelingalongside the roadway to be paved. The belt conveyor 22 can be moved outwardly to the position shown in FIG. 2 to receive concrete from a delivery vehicle moving alongside the spreader.

Thebelt conveyor 22 comprises a first concrete-receiving section that is substantially horizontally disposed whenthe conveyor is in the outer position shown in FIGS. 2 and 4, and a second section which is inclined upwardly toward the spreader l0 and which terminates at approximately the middle of the roadway. In the outer position, the conveyor discharges onto the center portion of the roadway the concrete received from the delivery vehicle. 7

An alternate form of concrete-receiving conveyor 12] is shown in FIG. 7 and comprises a belt conveyorv 122 that is formed of two sections 123 and 124. The first section 123 is upwardly inclined over the grade toward the spreader l0 and is rigidly mounted on the frame 12. The second section 124 is pivotally movable between the horizontally extending or down position and the vertically extending or up" position shown in solid and broken lines, respectively, in FIG. 7. Any suitable power means may be utilized to move the second conveyor section 124, such as the pistonand cylinder fluid drive unit 125 connected to brackets 126 and 127 on the first and second conveyor sections. The drive unit may be operated from the control deck 16 or from a position on the spreader 10 adjacent to the conveyor 122. In assembling the. spreader l0, conveyor 22 or conveyor 122 may be placed to extend to. the right or to the left side of the machine.

The discharged concrete is initially spread laterally over the roadway by a substantially horizontally disposed, elongated blade member 27 that is secured atone end to a vertically extending rod 28 that is rotatably mounted on the frame 12. The rod 28 and the blade member '27 are causedto oscillate by any suitable power means such as the pistonand cylinder fluid drive unit 29 connected to the rod 28, as shown in FIG. 2.

The concrete is further spread and distributed evenly over the roadway by augers 30 that are rotatably mounted on and extend across the carriages 11. The augers 34) are rotatably driven by the power means in any suitable or conventional manner. A strikeoff 31 is mounted on and extends across the carriages 11 immediately behind the augers and serves to strike off the spread concrete at a predetermined height, as

shown in FIG. 3. The strikeofi 31 may be adjustably mounted on the carriages 11 in any suitable or conventional manner.

As shown in FIGS. 2 and 3, continuous reinforcing rods R are supported on the spreader 10 to the two forward lift rolls 32 and 33 mounted on the carriages l1 and the frame 12, respectively; by the two rearward support rolls 34 and 35 mounted on the frame 12 and the carriages 11, respectively; and by spacer rolls 36 supported at the rear of the spreader and near support roll 35. in this manner, the reinforcing rods R are lifted from grade G and pass over the concrete conveyor 21 as the spreader 10 moves forwardly along the roadway to be paved. The rods R pass between beams 14 and deck 16. As shown in FIG. 4, deck 16 is supported on beams 14 by several narrow crossmembers 37, the intermediate crossmembers being disposed between adjacent rods R.

As shown in FIGS. 5 and 6, a second machine or finisher 40 trails the spreader 10 and may be of any suitable construction such as that shown in US. Pat. No. 3,331,296. In the preferred embodiment, the finisher 40 comprises a pair of endless tracklaying carriages 41 which operate on the grade 6 at each side of the concrete slab C formed by the spreader 10. A support frame 42 is mounted on the carriages 41 and serves to support an operator deck 43 and power means 44 for the finisher 40. v Each carriage 41 includes an inwardly facing slip form 45 which defines a side edge of the finished concrete slab C. The finisher 40, like the spreader 10, may be guided by probes (not shown) which move along a guide wire (not shown), or in any other conventional or suitable manner.

The continuous reinforcing rods R are supported and maintained in a predetermined spaced relationship at the front end of the finisher 40 by a pair of support rolls 46 and spacer rolls 47 that are mounted on the carriages 41. A walkway 48 extends across the carriages 41 and comprises a forwardly extending platform 49 that is disposed above the support rolls 46 and spacer rolls 47. The purpose of the platform 49 is to enable a workman to place tie bars T on the concrete and under the reinforcing rods R in transverse relation therewith, as shown in FIGS. 5 and 6, at the centerline of the roadway. Alternatively, suitable apparatus (not shown) could be provided on the platform 49 for automatically placing tie bars T at a predetermined spacing under the rods R.

Rearwardly of the walkway 48, a rod depressor 50 extends across and is rotatably mounted on the carriages 41. The depressor 50 is drivingly connected to the power means 44 in any suitable manner. The depressor 50 comprises a plurality of transverse members 51 extending across the carriages 411. The transverse members 51 are secured to the peripheries of the circular support members 52 and are spaced evenly about the periphery thereof. The rod members 51 are positioned to engage the upper surface of the reinforcing rods R and to depress the rods R and the underlying tie bars T a predetermined depth into the poured plastic concrete slab C as the finisher 40 moves forwardly.

Rotatable augers 53, drivingly connected to the power means 44, and a strikeoff 54 extend across and are mounted on the carriages 41 rearwardly of the depressor 50 for the purpose of spreading and striking off the agitated concrete at a predetermined height. A finisher member 55 is mounted on the carriages rearwardly of strikeoff 54 and serves to finally finish the upper surface of the concrete slab C.

In the method of the present invention, the continuous reinforcing rods R are placed on the grade G to be paved in a parallel manner. Such reinforcing rods R are typically supplied in 40 to -foot lengths which are laid on the grade and joined end to end by welding or by wrapping with wire (not shown) to provide continuous rods. As the spreader 10 is moved forwardly, the continuous reinforcing rods R are supported over the grade to be paved and above the concrete conveyor 21 by the lift rolls 32, 33 and the support rolls 34,

35, and are maintained in a predetermined spaced relationship 5 by the spacer rolls 36. The concrete deposited on the roadway by the conveyor 21 is spread by the oscillating blade 27 and the auger 30, and the upper and side surfaces of the concrete slab C are formed by the strikeofi' member 31 and the slip forms 20, respectively.

Tie bars T are then placed on the poured concrete slab C under the reinforcing rods R by a workman or by suitable apparatus (not shown) on the front platform 49 of the second machine or finisher 40. The reinforcing rods R and underlying tie bars T are then depressed a predetermined depth into the plastic concrete by the rotating depressor 50 as the finisher 40 moves forwardly. Tl-le agitated concrete is thereafter spread by the rotating auger 53, struck off at a predetermined height by the strikeoff 54, and finished by the finishing member 55 and the slip forms 45 as the finisher 40 continues to advance. 20 If it is desired to place full-width crossbars B instead of short tie bars T under the reinforcing rods R, a rear platform 60 may be provided on the spreader 10, as shown in FIG. 8, instead of the front platform 49 on the finisher 40. The cross bars B may be placed on the concrete slab C under the rods R either manually or by suitable apparatus (not shown) on the platform 60. Also, the tie bars T could be dispensed from the rear spreader platform 60 instead of the front finisher platform 49.

I claim:

1. Flrst and second concrete-paving machines for laying a concrete roadway with continuous longitudinal reinforcement rods embedded therein at a predetermined depth and spacing, said rods being preassembled on the grade on which the roadway is to be laid, each machine having spaced track means for operation on each side of the grade and a frame connecting said track means and extending over the grade; said first machine including a forward series of rolls disposed to pick up, elevate and guide said preassembled rods in a parallel array over the frame thereof as the machine travels and having power means carried by and above the frame on vertical struts between certain of said rods, a conveyor carried by and below said frame and projecting from the side of the machine to receive delivered concrete and having a discharge end at substantially the center of the grade and below the frame and the elevated rods, said first machine further including concrete distribution means below said discharge end of the conveyor, spreading means extending across the grade below the rods, and a series of rolls rearward of the machine to lower and guide the rods onto the spread concrete; said second machine including power means and forward rolls to guide and depress the rods into the concrete and intermediate and rearward means to respread and finish the surface thereof, said machines being independently operable as required and with variable spacing therebetween with or without allowing the rods to rest on the concrete therebetween.

2. Apparatus for placing reinforcing material in concrete paving, comprising:

a. means movable over the grade to be paved for lifting and supporting the reinforcing material above the grade;

b. means for receiving concrete from alongside the grade, conveying it beneath the raised reinforcing material onto the grade, and spreading it on the grade beneath the raised reinforcing material;

c. means for depressing the reinforcing material below the surface of the concrete on the grade; and

d. means for spreading the concrete over the depressed reinforcing material.

3. Apparatus for placing longitudinal, continuous reinforcing rods in a predetermined, spaced, substantially parallel relationship in concrete paving, comprising:

a. means movable over the grade to be paved for lifting and supporting the reinforcing rods above the grade;

b. means for receiving concrete from alongside the grade, conveying it beneath the raised rods onto the grade, and spreading it on the grade beneath the raised rods;

c. means for guiding and depressing the rods in said predetermined relationship below the surface of the concrete on the grade; and

d. means for spreading the concrete over the depressed rods.

4. Apparatus as in claim 3 wherein said means for lifting and supporting the rods and said concrete receiving and conveying means are mounted on a first machine movable over the grade, and said depressing means and said means for spreading the concrete over the depressed rods are mounted on a second machine movable over the grade.

5. Apparatus as in claim 4 wherein said supporting means of said lifting and first machine comprises support rolls positioned near the front and rear of said first machine, and spacer rolls for maintaining said rods in said predetennined relationship.

6. Apparatus as in claim 4 wherein said concrete receiving and conveying means comprises a transversely extending conveyor that is movable between a first position wherein it extends laterally a sufficient distance from said first machine to receive concrete from a delivery vehicle and a second position wherein it does not extend laterally a substantial distance from said first machine.

7. Apparatus as in claim 6 wherein said conveyor is mounted on a frame that is slidably movable on said first machine between said first and second positions.

8. Apparatus as in claim 6 wherein said conveyor is mounted on a frame that is pivotally movable on said first machine between said first and second positions.

9. Apparatus as in claim 4 wherein said first machine further comprises means positioned rearwardly of said concrete receiving and conveying means for spreading concrete and for forming it into a slab of predetermined size and shape.

10. Apparatus as in claim 9 wherein said concrete-spreading means comprise a horizontally disposed, oscillatable blade member positioned beneath said conveying means, and a rotatable auger extending transversely across said first machine and positioned rearwardly of said blade member.

11. Apparatus as in claim 4 wherein said first machine further comprises means on the rear portion thereof for enabling transverse reinforcing bars to be positioned onto the concrete under said rods and to be depressed into the concrete with said rods by said second machine.

12. Apparatus as in claim 4 wherein said depressing means comprises a plurality of transversely extending rod members adapted to engage said reinforcing rods to depress them into the concrete, said rod members being secured at their ends to circular support members and being spaced about the periphery thereof, said rod members and said support members being rotatable on said second machine.

13. Apparatus as in claim 4 wherein said second machine further comprises means positioned forwardly of said depressing means for enabling transverse reinforcing bars to be positioned onto the concrete under said rods.

14. Apparatus as in claim 4 wherein said second machine further comprises means positioned forwardly of said depressing means for supporting said rods in said predetermined relationship.

15. Apparatus as in claim 3 further comprising means for supporting transversely extending reinforcing bars so that they can be placed on the concrete prior to the depressing of the rods and so that the bars will be positioned beneath the rods and will be depressed into the concrete with the rods.

16. Flrst and second concrete-paving machine for laying a concrete roadway having continuous longitudinal reinforcing rods embedded therein at a predetermined depth and spacing, each machine having propelling means for travel over the grade on which the rods are preassembled and on which the concrete is to be laid; said first machine comprising a forward series of rolls disposed to elevate and guide said rods in a parallel array over the machine as it travels, a conveyor projectable from the side of the machine to receive delivered concrete and extending below the elevated rods to place the concrete on the grade, concrete distributing and spreading nine-u means disposed below the elevated rods and rearward of said conveyor, and a series of rolls on the rear portion of the machine to lower and guide the rods toward the spread concrete; said second machine comprising forward means to 5 guide and depress the rods into the concrete, and intermediate and rearward means to respread and finish the surface thereof.

17. A concrete-roadway-paving machine for operation over the grade on which the continuous longitudinal reinforcement bars for such concrete have already been laid and alongside which the concrete is to be delivered, said bars being of the type which are adapted to be depressed into the concrete after such concrete has been spread and while it is plastic, said machine comprising spaced track means for operation on each side of the grade, a frame connecting said track means and extending over the grade, a forward series of rolls disposed to pick up, elevate and guide said rods in a parallel array over the frame thereof as the machine travels over the grade, a conveyor carried by and below said frame and having a section which may be projected from the side of the machine to receive the delivered concrete and having a discharge end at the center of the grade and below the frame and the elevated rods, concrete-spreading means extending across the grade below the rods, and a series of rolls rearward of the machine to lower and guide the rods onto the spread concrete.

18. Apparatus as in claim 17 wherein the machine includes power means supported by said frame and over said rods on struts between certain of said rods.

19. A concrete-roadway-paving machine for operation over the grade on which the interconnected reinforcement for such concrete has already been laid and alongside which the concrete is to be delivered, said reinforcement being of the type which is adapted to be depressed into the concrete after such concrete has been spread and while it is plastic, said machine comprising spaced track means for operation on each side of the grade, a frame connecting said track means and extending over the grade, a forward series of rolls disposed to pick up, elevate and guide said reinforcement over the frame thereof as the machine travels over the grade, a conveyor carried by and below said frame and having a section which may be projected from the side of the machine to receive the delivered concrete and having a discharge end at the center of the grade and below the frame and the elevated reinforcement, concrete-spreading means carried by and below said frame and extending across the grade, and a series of rolls rearward of the machine to lower and guide the reinforcement onto the spread concrete.

20. Apparatus for concrete paving with longitudinal, continuous reinforcing rods placed in a predetennined spaced parallel relationship and transverse reinforcing bars disposed therebeneath at a predetermined elevation in the paving, said apparatus comprising a series of machines movable over the grade to be paved and together including:

a. means for progressively lifting a section of the rods which have been positioned and assembled on the ground ahead of the machines and for supporting said elevated section;

b. means for receiving and placing the concrete across the 3 grade beneath said elevated section of rods;

0. a platform for supporting beneath said elevated section of rods a supply of transverse reinforcing bars for positioning on the spread concrete beneath said elevated section of rods;

d. means for lowering and spacing the rods whereby they are supported in said predetermined, spaced relationship by the spread concrete;

e. means for depressing the spaced rods below the surface of the spread concrete such that said rods depress said bars to said predetermined elevation, and

f. means for spreading the concrete over the depressed reinforcing rods and bars.

21. Apparatus as in claim 20 wherein said lifting and supporting means comprises support rolls positioned near the front and rear of the first machine, and said means for spacing the rods as they are lowered in said predetermined, spaced 75 relationship comprise spacer rolls.

circular support members and being spaced about the periphery thereof, said rod members and said support members being rotatable by and with the forward movement of the machine carrying the same.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No- 34 611.890 Dated Qntnher 19 W71 Inventor(s) Michael I Hudis It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

IN THE SPECIFICATION:

Line 15 Line 24 Column 1, "laying" instead of "layihg" "and" instead of "ans" IN THE CLAIMS:

Column 5, Lines l2, 13 should read "said lifting .and

supporting means of said first Signed and sealed this 2nd day of May 1972.

(SEAL) Attest:

EDWARIS M.FLE1CHER, JR. Attesting Officer ROBERT GOTTSCHALK Commissioner of Patents ORM PO-WEO 7 USCOMM-DC 6J378-P69 ii U.S GOVERNMENT PRINTING OFFICE I09 O-3lG-33 

1. FIrst and second concrete-paving machines for laying a concrete roadway with continuous longitudinal reinforcement rods embedded therein at a predetermined depth and spacing, said rods being preassembled on the grade on which the roadway is to be laid, each machine having spaced track means for operation on each side of the grade and a frame connecting said track means and extending over the grade; said first machine including a forward series of rolls disposed to pick up, elevate and guide said preassembled rods in a parallel array over the frame thereof as the machine travels and having power means carried by and above the frame on vertical struts between certain of said rods, a conveyor carried by and below said frame and projecting from the side of the machine to receive delivered concrete and having a discharge end at substantially the center of the grade and below the frame and the elevated rods, said first machine further including concrete distribution means below said discharge end of the conveyor, spreading means extending across the grade below the rods, and a sEries of rolls rearward of the machine to lower and guide the rods onto the spread concrete; said second machine including power means and forward rolls to guide and depress the rods into the concrete and intermediate and rearward means to respread and finish the surface thereof, said machines being independently operable as required and with variable spacing therebetween with or without allowing the rods to rest on the concrete therebetween.
 2. Apparatus for placing reinforcing material in concrete paving, comprising: a. means movable over the grade to be paved for lifting and supporting the reinforcing material above the grade; b. means for receiving concrete from alongside the grade, conveying it beneath the raised reinforcing material onto the grade, and spreading it on the grade beneath the raised reinforcing material; c. means for depressing the reinforcing material below the surface of the concrete on the grade; and d. means for spreading the concrete over the depressed reinforcing material.
 3. Apparatus for placing longitudinal, continuous reinforcing rods in a predetermined, spaced, substantially parallel relationship in concrete paving, comprising: a. means movable over the grade to be paved for lifting and supporting the reinforcing rods above the grade; b. means for receiving concrete from alongside the grade, conveying it beneath the raised rods onto the grade, and spreading it on the grade beneath the raised rods; c. means for guiding and depressing the rods in said predetermined relationship below the surface of the concrete on the grade; and d. means for spreading the concrete over the depressed rods.
 4. Apparatus as in claim 3 wherein said means for lifting and supporting the rods and said concrete receiving and conveying means are mounted on a first machine movable over the grade, and said depressing means and said means for spreading the concrete over the depressed rods are mounted on a second machine movable over the grade.
 5. Apparatus as in claim 4 wherein said supporting means of said lifting and first machine comprises support rolls positioned near the front and rear of said first machine, and spacer rolls for maintaining said rods in said predetermined relationship.
 6. Apparatus as in claim 4 wherein said concrete receiving and conveying means comprises a transversely extending conveyor that is movable between a first position wherein it extends laterally a sufficient distance from said first machine to receive concrete from a delivery vehicle and a second position wherein it does not extend laterally a substantial distance from said first machine.
 7. Apparatus as in claim 6 wherein said conveyor is mounted on a frame that is slidably movable on said first machine between said first and second positions.
 8. Apparatus as in claim 6 wherein said conveyor is mounted on a frame that is pivotally movable on said first machine between said first and second positions.
 9. Apparatus as in claim 4 wherein said first machine further comprises means positioned rearwardly of said concrete receiving and conveying means for spreading concrete and for forming it into a slab of predetermined size and shape.
 10. Apparatus as in claim 9 wherein said concrete-spreading means comprise a horizontally disposed, oscillatable blade member positioned beneath said conveying means, and a rotatable auger extending transversely across said first machine and positioned rearwardly of said blade member.
 11. Apparatus as in claim 4 wherein said first machine further comprises means on the rear portion thereof for enabling transverse reinforcing bars to be positioned onto the concrete under said rods and to be depressed into the concrete with said rods by said second machine.
 12. Apparatus as in claim 4 wherein said depressing means comprises a plurality of transversely extending rod members adapted to engage said reinforcing rods to depress them into the concrete, said rod members being secured at their ends to ciRcular support members and being spaced about the periphery thereof, said rod members and said support members being rotatable on said second machine.
 13. Apparatus as in claim 4 wherein said second machine further comprises means positioned forwardly of said depressing means for enabling transverse reinforcing bars to be positioned onto the concrete under said rods.
 14. Apparatus as in claim 4 wherein said second machine further comprises means positioned forwardly of said depressing means for supporting said rods in said predetermined relationship.
 15. Apparatus as in claim 3 further comprising means for supporting transversely extending reinforcing bars so that they can be placed on the concrete prior to the depressing of the rods and so that the bars will be positioned beneath the rods and will be depressed into the concrete with the rods.
 16. FIrst and second concrete-paving machine for laying a concrete roadway having continuous longitudinal reinforcing rods embedded therein at a predetermined depth and spacing, each machine having propelling means for travel over the grade on which the rods are preassembled and on which the concrete is to be laid; said first machine comprising a forward series of rolls disposed to elevate and guide said rods in a parallel array over the machine as it travels, a conveyor projectable from the side of the machine to receive delivered concrete and extending below the elevated rods to place the concrete on the grade, concrete distributing and spreading means disposed below the elevated rods and rearward of said conveyor, and a series of rolls on the rear portion of the machine to lower and guide the rods toward the spread concrete; said second machine comprising forward means to guide and depress the rods into the concrete, and intermediate and rearward means to respread and finish the surface thereof.
 17. A concrete-roadway-paving machine for operation over the grade on which the continuous longitudinal reinforcement bars for such concrete have already been laid and alongside which the concrete is to be delivered, said bars being of the type which are adapted to be depressed into the concrete after such concrete has been spread and while it is plastic, said machine comprising spaced track means for operation on each side of the grade, a frame connecting said track means and extending over the grade, a forward series of rolls disposed to pick up, elevate and guide said rods in a parallel array over the frame thereof as the machine travels over the grade, a conveyor carried by and below said frame and having a section which may be projected from the side of the machine to receive the delivered concrete and having a discharge end at the center of the grade and below the frame and the elevated rods, concrete-spreading means extending across the grade below the rods, and a series of rolls rearward of the machine to lower and guide the rods onto the spread concrete.
 18. Apparatus as in claim 17 wherein the machine includes power means supported by said frame and over said rods on struts between certain of said rods.
 19. A concrete-roadway-paving machine for operation over the grade on which the interconnected reinforcement for such concrete has already been laid and alongside which the concrete is to be delivered, said reinforcement being of the type which is adapted to be depressed into the concrete after such concrete has been spread and while it is plastic, said machine comprising spaced track means for operation on each side of the grade, a frame connecting said track means and extending over the grade, a forward series of rolls disposed to pick up, elevate and guide said reinforcement over the frame thereof as the machine travels over the grade, a conveyor carried by and below said frame and having a section which may be projected from the side of the machine to receive the delivered concrete and having a discharge end at the center of the grade and below the frame and the elevated reinforcement, concrete-spreading meaNs carried by and below said frame and extending across the grade, and a series of rolls rearward of the machine to lower and guide the reinforcement onto the spread concrete.
 20. Apparatus for concrete paving with longitudinal, continuous reinforcing rods placed in a predetermined spaced parallel relationship and transverse reinforcing bars disposed therebeneath at a predetermined elevation in the paving, said apparatus comprising a series of machines movable over the grade to be paved and together including: a. means for progressively lifting a section of the rods which have been positioned and assembled on the ground ahead of the machines and for supporting said elevated section; b. means for receiving and placing the concrete across the grade beneath said elevated section of rods; c. a platform for supporting beneath said elevated section of rods a supply of transverse reinforcing bars for positioning on the spread concrete beneath said elevated section of rods; d. means for lowering and spacing the rods whereby they are supported in said predetermined, spaced relationship by the spread concrete; e. means for depressing the spaced rods below the surface of the spread concrete such that said rods depress said bars to said predetermined elevation, and f. means for spreading the concrete over the depressed reinforcing rods and bars.
 21. Apparatus as in claim 20 wherein said lifting and supporting means comprises support rolls positioned near the front and rear of the first machine, and said means for spacing the rods as they are lowered in said predetermined, spaced relationship comprise spacer rolls.
 22. Apparatus as in claim 20 wherein said depressing means comprises a plurality of tranversely extending rod members adapted to engage said reinforcing rods to depress them into the concrete, said rod members being secured at their ends to circular support members and being spaced about the periphery thereof, said rod members and said support members being rotatable by and with the forward movement of the machine carrying the same. 